Electromagnetic relay with banks of resilient contact members



Jan. 25, 1966 MASAO HlYANE ELECTROMAGNETIC RELAY WITH BANKS OF RESILIENT CONTACT MEMBERS 4 Sheets-Sheet 1 Filed Jan. 29, 1962 5} 27 loofoooooo Q e'e e @33 0 O0 O0 00 CO 00 0000 00g ELECTROMAGNETIC RELAY WITH BANKS OF RESILIENT CONTACT MEMBERS Filed Jan. 29, 1962 Jan. 25, 1966 MASAO HlYANE 4 Sheets-Sheet 2 Jan. 25, 1966 MASAO HIYANE ELECTROMAGNETIC RELAY WITH BANKS OF RESILIENT CONTACT MEMBERS 4 Sheets-Sheet 5 Filed Jan. 29, 1962 FIG.7

Jan. 25, 1966 MASAO HIYANE ELECTROMAGNETIC RELAY WITH BANKS 0F RESILIENT CONTACT MEMBERS Filed Jan. 29. 1962 4 Sheets-Sheet 4 w m m L m a a y E M 8 w m M -2 6 G e 0 I A. M F, W M p a 4 u M w e M 4 4% m J e 5 @w n 0 0 ma m m m 05 0.7 fw/n/ United States Patent Claims. (a. 200-104 My invention relates to spring wire relays of the multi-contact type for use in electrical equipment such as telephone systems.

For the purpose of supporting contact-making pieces, such relays have spring wires arranged in a multiplicity of parallel lines. Each spring wire is cantilevered by being embedded at one end into a plastic holder. The plastic holder fixes the other end of these wires relative to the electro-magnetic core of the relay into groups of stationary and movable spring wires corresponding to the purpose of the relay. A fixed insulating plastic bar or plate embraces and supports the movable wires near their free ends and controls the movable spring wires.

Attempts to reduce the size of the relays in conformance with the modern technological trend toward miniaturization prove difficult for a number of reasons. In view of the stress that must be applied to the wires for deflecting them, it is diflicult to shorten spring wires to less than a critical length. Reduction of the wire diameter introduces technical and manufacturing complications. Even if the obstacles to obtaining small diameter wires of uniform quality were overcome, there still would remain the problem of producing supporting bars or plates with suflicient mechanical strength to adequately resist the flexure of the wires. There also appears the problem of effectively securing contact metal pieces to the re spective tips of such fine wires.

It is an object of my invention to eliminate the disadvantages of, and the obstacles to, miniaturizing conventional spring-wire relays.

According to a feature of my invention, I fasten one end of each spring Wire to an insulated holder, and I provide each spring wire with a flattened portion along its length. I thus afford shortening the length of the wire far more than would be otherwise attainable for particular conditions of allowable stress, deflection and load at the free end. Moreover, I suitably arrange a specific number of these spring wires in parallel lines with their respective free ends placed across the upper or bottom side of a stop bar and adjust them in a holder so that they are transversely pressed against the stop bar or abutment by virtue of their own elasticity. I position the electrical contact on each spring wire upon the face or side of the spring wire which abuts against the abutment bar so that pressure applied to the contact disengages the free end of the spring wire from the abutment bar against the elastic force of the spring wire. Confronting the stationary contacts on the spring wires I locate respective movable contacts attached to the respective free ends or tips of other ice Therefore, because I flatten the wires, these will deflect to a sufficient extent under small load.

For a more complete understanding of the invention reference may be had to the following description when taken together with the accompanying drawings wherein:

FIG. 1 is a simplified side view of a spring-Wire relay according to the invention;

FIG. 2 is a cross section of the spring-wire relay taken along the line A-B in FIG. 1;

FIG. 3 is a plan view of the device in FIG. 1 partially broken away along the line C-D in FIG. 2;

FIG. 4 is an exploded view of the relay in FIG. 1;

FIG. 5 is a perspective view of a jack adapted to receive the relay according to FIG. 1 and also embodying features of the invention;

FIG. 6 is an exploded view of another armature assembly also embodying features of the invention and adapted to replace the armature assembly shown in FIG. 4;

FIG. 7 is a schematic diagram showing an approximate magnetic equivalent circuit of the spring-wire relay according to the invention;

FIG. 8 is a characteristic curve showing the magnetic pole force imparted to the armature by the core of the relay according to the invention;

FIG. 9 is a detail perspective view of a spring wire employed by the relay according to the invention; and

FIG. 10.1are characteristic curves of the upper and lower limits of wire length relative to wire diameter under a maximum allowable stress with specific flexure.

In FIGS. 1 to 4, wherein like numerals designate like parts, the relay unit according to the invention includes an E-shaped core 11 with an excitation coil 12 wound around the central leg of the core. A C-shaped softmagnetic armature holder 13 bridges the outer legs of the core 1 1 and supports an armature 14. The armature holder 13 bridging the outer legs of core 11 includes a central humped bridging portion 13a and a pair of outer flat pedestals 16 secured to the outer legs of the core 11 by fastening members passing through aligned holes 16 and I l. The armature 14 hangs by a pair of square holes 17 which receive a pair of projection lugs 15 integrally united with the armature holder 13. A pair of contact-springdriving arms 1 8 extends toward the core from the armature 14 and'terminates in upward :bends supporting plastic caps 19.

A cross-member 26 forming part of a contact-biasing assembly 26' integrally includes a horizontal T-shaped brace 37 projecting therefrom and having a pair of holes 37'. The T-brace 3-7 is secured upon the bridge 13a of the armature holder 13 by fastening members (not shown) passing through holes 37' aligned with the holes 13. Extending outwardly from the center of member 26 and terminating in upward bends are a pair of leaf springs 38 which bear against a pair of indentations 20 upon the armature 14. The leaf springs 38 thus lightly bias the armature in a clockwise direction as viewed in FIGS. 1 and 4 about the lugs 15 which behave as a fulcrum, and also against the lugs 15. The clockwise biasing force of the leaf springs 38 against the armature indentations 20 forces the armature against a downwardly extending armature finger 36 to establish the biased armature position. The member 26 furthermore extends outwardly in a horizontal direction in two support arms 35 which terminate in vertical S-shaped spacer bar supports 39. A spring-wire-separating and insulating spacer bar 34 is located above the T-brace 37 and fits into a pair of recesses formed by the S-shaped spacer bar supports 39.

A plurality of spring wires 21 pass through a fixed flat offset insulated plastic holder 27 and a floating flat insulated plastic holder 28, each embedding portions of the wires 21. The wires terminate at the end near holder 28 in rectangular-block contact pieces 29 at the end near holder 27 in contact-making plugs 41. The wires 21 include flattened sections 30 between the two insulated holders 27 and 28. As seen in FIG. 2 a pair of plastic holders 33 and 32 sandwich the plastic holder 27 between them and secure it upon the cross-member of the E-shaped core 11. The holders 32, 33 embed portions of a plurality of bent parallel wires 23 extending generally in the direction of the wires 21 and resting by virtue of their bends and their elasticity upon the bar 34. The wires extending from the holder 32 are collectively and generally designated 2 5. A plurality of wires 23 collectively and generally designated 24 extend in parallel relation from the holder 33 underneath the wires 22 and rest with their ends, by virtue of their bends and elasticity, against the lower surface of bar 34. The wires 23 constitute the stationary springs. As stated, they form approximately two symmetrical groups 24 and 25 above and below the movable contact springs 22. The Wires belonging to the group 24 each possess on their respective undersides make contacts confronting the rectangular contacts 29. The group of wires designated 25 possess on their upper faces break contacts confronting the contacts 29. As stated, each of the wires 23 in the groups 24 and 25 are partially flattened and bent toward the movable contact spring 22 and owing to the elasticity resulting from such bent shape they are pressed tightly against the bar 34. The bar 34 performs the function of determining the relative position of individual wires 21 and 23 as well as separating the wire groups 24 and 25.

By virtue of the partial flattening of spring wires 21 and 23, the whole structure of the relay is rendered compact. The assembly work is considerably simplified by the provision of the bar 34 for accurately maintaining the tips of the wires 23 at prescribed positions and by the existence of the armature stopper 336 and the leaf springs 38 for maintaining the armature upon the armature holder.

As may more particularly be seen in FIG. 1, the insulated holder 28 rests flatly upon the caps 19. The wires 21 are bent and embedded within the holder 27 in such a way as to bias downwardly the caps 19 and the entire armature 14 about the fulcrum lugs 15. This reinforces the light bias of the leaf springs 38. The resilient wires 21 further press downwardly with suflicient force to press contact 29 against the contacts upon the wires in group 25 with sufficient force to accomplish extremely good contact. The degree of contact is enhanced by allowing the contacts 29 to push the wires in group 24 from their resting places upon the bar 34. The limit stop on assembly 26 limits the position to which the holder 28 can rotate the armature 14.

A metal U-shaped yoke 61 and bracket 62 embrace the insulated holders 33, 27 and 3-2 which are stacked to form a single column. The yoke 61 terminates in two bar hooks 63 which engage two bar protrusions 64 upon the bracket 62. The bracket 62 is comprised of an elastic metal plate bent into a shallow W-shape and provided with a hole 66 receiving a clamping bolt 65 (see FIG. 2). The bracket 62 sits on the bottom of the core 11 with its protrusion 64 engaging the bar hooks 63 of the yoke 61. The bolt 65 passes through the hole 66 and threadingly engages a tap hole bored into the cross-member of the E- shaped core 11. Tightening of the bolt 65 presses the central protruding part of the clamping bracket 62 forcing protrusions 64 downward. This in turn presses the bar hooks 63 and pulls the yoke 61 to securely bind together the holders 32, 27 and 33 with the core 11.

When the coil 12 is tie-energized and the relay core 11 carries little or no magnetic flux, the following conditions prevail. The springs 23 of the group 25 press resiliently against the bar 34 and the position of their end contacts on the springs is precisely determined by the bar. The armature -14 is securely pressed by leaf springs 38 against the holder 13. The movable spring wires 21 have their movable contacts aligned'by the holder 28. The spring wires 21 resiliently press the armature 14 against the back stop 36.

'Energization of the coil 12 and the core 11 attracts the armature 14 to the core 11 and rotates the armature 14 about the fulcrum lugs 15. Consequently, the caps 19 lift the wire rods 21 by way of the holder 28 and produce contact between the precisely aligned contacts 29 and the similarly aligned wires 23 in group 25. The alignment of the contact on the spring wires 23 of group 25 by the bar 34 thus insures unfailing contact with the aligned contact 29.

The relay also forms a plug-in junction unit for ready operation. This unit includes plug contacts constituted by the fixed ends 41 of each spring wire 21 projecting from behind the insulated holder 27 with a pointed tip. The ends 41 of the wires 21 have a diameter of, for example, .55 mm. and exhibit high mechanical strength. The insulated holders 32 and 33 through which the wires 21 project, integrally include insulated, rearwardly projecting, parallel plate guides 43. The upper face of the upper plate guide 43 on holder 32 exhibits a number of grooves 42. Similarly the lower face of plate guide 43 of holder 33 exhibits a number of similar grooves. These grooves carry the projected ends 44 of the wires 23. The wires 23 are folded back upon themselves into flattened sections 45. The wires 23 have a smaller diameter, e.g., .35 mm, than the wires 21 and are each paired with adjacent ones to form a double contact at their ends 44. Hence each pair of wires rests in a common groove separated from a neighboring pair by an insulated groove wall.

A jack box (see FIG. 5) for utilizing the plug includes an insulated base 46 molded out of material such as plastic, socket spring contactors 47 that correspond to the plug contactors 41, and socket contactors 48 for connection with the flattened contactors 45. The base 46 defines a rear wall and a space 49. It includes on its upper and its lower sides flat conductive socket contactors 48. Since the plug contactors 45 include a flattened flexible portion, the mating socket contactors 48 are made of hard, comparatively thick conductive plates. The contactors 48 include bent tips 50. These engage indentations 51 which are provided along the side of the base 46 and are secured to the base 46 by means of buttons 54 provided on terminal bars 53. The terminal bars 53 are conductively joined with the contactors 48 and protrude backward to the rear wall of the base to square holes 52. While they are not so shown, the invention contemplates embedding the socket contactors in the base 46. Extending through the center of space 49, arranged side by side, are a row of bifurcated flat socket spring contactors 47. The socket spring contactors 47 protrude as soldering terminals 55 through separate square holes 56 guided by separators 58 and held fast by buttons 57 as well as by virtue of their own folds. in connecting the plug with the jack, the plug contactors 41 are inserted into the socket spring contac tors 47 while the plug contactors 45 slide into contact with the socket contactors 48. Since the contact spring seat is fastened to the core 11 by means of the yoke 61, the fix ture of the relay as a whole may operate as a plug-in connector. Accordingly, the guides 43 of the insulated holders 32 and 33 on the plug side are constructed so that they securely fit into the inner walls of the base 46 on the jack side in order to insure a tight connection...

Though the socket spring contactors 47 are constructed to avoid deflection to right or left by means of the guide walls 58, they can incline to some extent in the vertical direction for the purpose of permitting smooth insertion of the plugs. When the plugs move into the jack box, the tips of the guides 43 press the folded ends of the socket spring connectors 47 into a suitable position so that the plug contactors 41 can be inserted smoothly into the spring contactors 47. After that, the contactors 47 are again tightened by the pressure of the guides 43 and maintained in good contact with the plug contactors 41.

excitation coil 12.

the reluctance Rh small.

FIG. 6 shows another example of the structure of the armature 14 and armature holder 13. Instead of having square holes at its upper edge, the armature 14 includes a bend 17 which is designed to abut against the edge of the armature holder 13. The abutment allows the armature to flap freely. When the core 11 is unenergized, the armature maintains its pivotal position relative to the core by virtue of the effect of leaf springs 38. When energized, the core 11 draws the armature in its direction. The remaining structural features are identical with those of the ones shown in FIG. 4.

FIG. 7 schematicallyrepresents the-electromagnetic circuit of the device in FIG. 4. The source 41rNI in FIG 7 represents the magnetornotive force produced by the Ry represents the reluctance of the gap between the magnetic pole tip of the outer legs of the core 11 and the armature 14. This is in series with the magnetic reluctance R0 arising from the gap of the central pole tip of the core 11 and the armature 14. Parallel to the magnetic reluctance Ry there exists Rh representing the reluctance of the armature holder 13 as Well as the reluctance between the armature holder 13 and the armature 14. In series with the reluctance Ro exists a reluctance Rc of the core 11.

Assuming that the flux o represents the total magnetic flux passing through reluctance R0, and h and y represent the respective magnetic fluxes through the relucitances Rh and Ry, the values 0 and qty together with the pull force F exerted upon the armature 13 can be calculated. Such calculation neglects leakage flux in order to simplify the explanation. This approximation is comparatively accurate unless the core material is not magnetically saturated. It is desired that the effect of stretching out the pole face area is obtained by making magnetic attractive force when the armature lies at a comparatively great distance from the pole.

Let So be the tip-pole area of the center leg of iron core 11 and Sy be the tip-pole area of both sides, then attraction P which armature 14 receives is written as That is, there prevails a large 6 The variation in F is derived from variation of -Z+ (ZWRT)2=A 11']. Equation 10. 1S,

y Ro-l-Rc Ro-l-Rc Q i 11 Ry SO dZ Ro-l-Rc 4 21 R0+Rc S y Ry S0 R0+Rc+ As already stated, What is now being dealt with is the case where armature 14 is still far from the pole-tip. Therefore, Rc is extremely small compared with R0 and Ry, and Equation 11 can be approximated as follows by neglecting R0.

when 2:1 and Rh=oo.

From the foregoing, it is clear that attraction F received by armature 14 increases if it is assumed that other factors are invariable and if magnetic resistance Rh decreases.

In the ordinary electrom'agnet mechanism for relays, in order to set attraction characteristics as prescribed, the area of the magnetic pole is made different from the cross section of the iron core, so that the area of the magnetic pole may be arranged properly. On the other hand, in the case of the electromagnet mechanism as shown in FIG. 4 or FIG. 6, it is clear from the foregoing explanation that it is possible to set the magnetic resistance Rh; in the armature holder 13 to a proper value and freely select the characteristic of the attracting force exercised on the armature 14, by varying the material, dimensions and shape -of the armature holder.

FIG. 8 represents the relation-ship between the attracting force F exercised upon the armature 14 and the armature stroke X obtained from experiments conducted on the electromagnetic mechanism shown in FIG. 4. Two kinds of armature holders were employed in the experiment. One of the armature holders was of brass and the other of iron while the respective materials of the core 11 in the armature 14 and the coil 12 remained the same. Gf the two curves shown in FIG. 8 the solid line corresponds vto the iron armature .holder and the dotted line corresponds to the brass holder. The ampere turns of the coil 12 were set at 140. This experimental dataverifies the conclusion set forth in the preceding paragraph. The electromagnetic mechanism, according to the invention, possesses a high operating efliciency because a slight protrusion of the central pole tip of the core 11 enables the leakage flux to remain at a minimum value. The resulting magneto-motive force required to obtain a specific attractive force decreases and accordingly it is possible to make the core more compact as well as making the coil much smaller. At the same time, a simple mechanism can support the armature 14 and the structure of the whole electromagnetic unit is considerably simplified while maintaining great rigidity.

Regarding the spring wires (FIGS. 9, some of the advantages of hitherto used wires are as follows. Spring wires can 'be manufactured with precise diameters and can be tightly fitted to insulating molds. Spring wires, however, cannot be shortened beyond critical length for a particular maximum allowable stress applied to them as well as for a particular deflection capacity. Generally the length l of a cantilever spring is expressed as where a is the maximum allowable stress, Z is the modulus of the section, w is the force applied to the free end of the cantilever, E is Youngs modulus, I is the secondary sectional moment and 6 is the desired flexure. Providing the respective values of 5, Z and w are given, we can determine the upper and lower limit of I from Equations 15 and 16 respectively.

Referring to FIG. 10, the curve I represents the relationship between the diameter and the upper limit of the length of a nickel-silver wire having a round cross section where E is equal to 13,000 kg./mm. w is equal to 7 g., and 0' is equal to kg./mm. Curves II and III represent the relationship between the wire diameter and the lower limit of the wire length when 6:1 and 6:3 respectively. Accordingly the points (a) and (b) where curve I intersects curves II and III correspond to the minimum values of both the wire diameter and the wire length at 6:1 and 6:3, respectively.

The spring wire used in the present invention in FIGS. 1 to 4 is flat in part whereby it is possible to make its flexure several times as large as that of traditional springs with a round cross section.

Referring to FIG. 9, a spring wire such :as that used in FIG. 4 of the invention is embedded at one end in an insulating mold of synthetic resin and the section covering the length kl possesses a flat shape. In the case of the spring shown in FIG. 9 its fiexure 6 is expressed as where ma=b/d while I represents the secondary sectional moment of the round part of the wire and is equal to Therefore the value of 6 has a value approximately three times as large as that of the wire with a round cross section. This makes it possible to set the minimum wire diameter and wire length at the values corresponding to point (b) in FIG. l0.

In accordance with the invention the wire can be advantageously used as a contact spring or restoring spring in the electromagnetic relay. The springs can occupy side by side positions within a small space. The spring wire of the flattened type as compared to the round wire inclines to a far greater extent at its free end for the same deflection than round wires and produces considerable sliding friction at the contact.

According to the invention the spring wire in its round form is first embedded in the insulated mold such as 32, 33 or 27 and directed in parallel "lines and then a specific length of section at the free end is flattened by means of a press. This machining procedure can, however, be reversed.

As a further point the spring wires 21 of FIGS. 1 to 4 are mounted for the pieces 29 to resiliently press against the wires 23 of group 25, when the coil 12 is not energized, and against the wires 23 of group 24 when the coil 12 is energized, with sufiicient force to afford good con-v tact. The invention contemplates the wires 23 being mounted so that the force is just enough to provide the good contact and also being mounted so that the force is greater, until it becomes suflicient to lift the contacted spring wires 23, in the appropriate group 24 or 25, from the bar 34.

While various embodiments of the invention have been described in detail, it will be obvious to those skilled in the art that the invention may be given embodiments other than particularly illustrated and described herein, without departing from the essential features of my invention land within the scope of the claims annexed hereto.

I claim:

1. A relay comprising a stationary resilient contact member, a stationary rest bar, means to bias said member against said rest bar, a movable resilient contact member contactable with said stationary member in the vicinity of said rest bar, armature means to move said movalble member in and out of contact with said stationary member and to thereby press said stationary member in a direction away from said bar, and electromagnetic means to control said armature means; said electromagnetic means including a core having pole portions, said armature means forming with said pole portions respective gaps, and a metal bridge structure of magnetizable material mounted between two of said pole portions for supporting said armature means and forming a shunt between said pole portions.

2. A relay comprising a stationary rest bar, an elongated stationary resilient contact member crossing said stationary rest bar, cantilever-type support means to bias said stationary member against said rest bar, a movable resilient contact member contactable with said stationary member in the vicinity of said rest bar, armature means to move said movable member in and out of contact with said stationary member and to thereby press said stationary member in a direction away from said rest bar, and electromagnet means to control said armature means; said electromagnetic means including a core having pole portions, said armature means forming with said pole portions respective gaps, and a metal bridge structure of magnetizable material mounted between two of said pole portions for supporting said armature means and forming a shunt between said pole portions.

3. A relay comprising a plurality of stationary resilient contact members, a stationary rest bar, means to bias said members against said rest bar, a plurality of movable contact members contactable with said stationary members in the vicinity of said bar, electromagnetic means to move said movable members in unison into and out of contact with said stationary members and during contact to press with said movable members said stationary members in a direction away from said bar; said electromagnetic means including a core having pole portions, said armature means forming with said pole portions respective gaps, and a metal bridge structure of magnetizable material mounted between two of said pole portions for supporting said armature means and forming a shunt between said pole portions.

4. A relay comprising an electromagnetic winding, a core magnetically interlinked with said winding and having magnetic pole portions, a bridge structure of magnetizable material mounted between two of said pole portions, a magnetic armature articulated from said bridge structure and hingedly movable toward and away from one of said pole portions according to the energization of said core, a stator electrical contact member having a relatively fixed position with respect to said core, a movable electrical contact member in the vicinity of the stationary contact member responsive to movement of said armature for contacting said stator contact member.

5. A relay comprising an electromagnetic winding, a core magnetically interlinked with said winding and having magnetic pole portions, a bridge structure of magnetizable material mounted between two of said pole portions and having projection means extending therefrom, a magnetic armature forming respective gaps with said pole portions and having projection receiving means loosely engaging said projection means to be articulated thereabout from said bridge structure, said armature being swingable toward one of said pole portions according to the energization of said one pole portion, resilient means to maintain the engagement between said projection means and said projection receiving means and to bias said armature in one direction, a stator electrical contact member having a relatively fixed position with respect to said core, a movable electrical contact member in the vicinity of the stationary contact member responsive to movement of said armature for contacting said stator contact member.

6. A relay comprising an electromagnetic winding, a core magnetically interlinked with said winding and having pole portions, a bridge structure of magnetizable material mounted between two of said pole portions, a magnetic armature forming respective gaps with said pole portions and hingedly engaged with said bridge structure so :as to move in the vicinity of said pole portions and swing toward said pole portions in accordance with the energization of said winding, said bridge structure including a projecting edge, said armature including a lip extending over said edge and engaging said edge, a stationary contact member, a movable contact member responsive to movement of said armature adapted to contact said stationary member, and resilient means to maintain the engagement between said edge and said lip.

7. A relay comprising an electromagnetic winding, 21 core magnetically interlinked with said winding and having pole portions, a bridge structure of magnetizable material mounted between two of said pole portions, a magnetic armature hingedly engaged with said bridge structure and adapted to move in the vicinity of one of said pole portions so as to swing toward said one pole portion in accordance with the energization of said winding, said bridge structure including a projecting edge, said armature including a lip extending over said edge and engaging said edge, a stationary contact member relatively fixed with respect to said core, a movable contact member responsive to movement of said armature adapted to contact said stationary member, and resilient means to maintain the engagement between said edge and said lip and to bias said swingable armature in one direction.

8. A relay comprising an E-shaped core having three parallel legs, the ends of legs of said core functioning as poles, an electromagnetic winding about the center leg of said core for energizing said core, a bridge structure of magnetizable material mounted upon the outer legs of said core, an armature flappingly engaged with said bridge structure and adapted for movement in the vicinity of the poles of said core so as to swing toward said poles in accordance with the energization of said winding, a stationary electrical contact member relatively fixed with respect to said core, and a movable electrical contact member responsive to movement of said armature for contact with said stationary member.

9. A relay comprising an E-shaped core having three parallel legs, the ends of legs of said core functioning as poles, an electromagnetic winding about the center leg of said core for energizing said core, a bridge structure of magnetizab-le material mounted upon the outer legs of said core, an armature flappingly engaged with said bridge structure and adapted for movement in the vicinity of the poles of said core so as to swing toward said poles in accordance with the energization of said winding, said bridge structure including a pair of feet secured upon the sides of respective outer legs of said core and an overpass section extending between said legs, a pair of projections extending from said overpass section, said armature having a fiat plate-like construction and projection receiving opening near one edge thereof, said openings and said projections being in engagement, resilient means connected to said bridge structure for biasing the openings in said armature into engagement with said overpass section, a stationary electrical contact member, and a movable electrical contact member responsive to movement of said armature for contact with said stationary contact member.

10. A relay comprising an E-shaped core having three parallel legs, the ends of legs of said core functioning as poles, an electromagnetic winding about the center leg of said core for energizing said core, a bridge structure of magnetizable material mounted upon the outer legs of said core, an armature flappingly engaged With said bridge structure and adapted for movement in the vicinity of the poles of said core so as to swing toward said poles in accordance with the energization of said winding, said bridge structure including a pair of feet secured upon the sides of respective outer legs of said core and an overpass section extending between said legs, an edge on said overpass section, said armature having a flat plate-like construction with a lip extending from one edge in engagement with the edge on said overpass, resilient means connected to said bridge structure for biasing said edges against each other, a stationary electrical contact member relatively fixed with respect to said core, and a movable electrical contact member responsive to movement of said armature for contact with said stationary contact member.

References Cited by the Examiner UNITED STATES PATENTS 2,069,169 l/1937 Leake 200104 2,069,171 1/1937 Merkel 200104 2,282,933 5/1942 Cahill 317177 2,794,888 6/1951 Morse 200166 2,866,030 12/1958 Wirth 200104 2,913,551 11/1959 Vigren et a1. 200166 2,970,200 1/1961 Walker et a1 200104 2,973,464 2/1961 Wiberg 317198 BERNARD A. GILHEANY, Primary Examiner.

G. S. HARRINGTON, T. D. MACBLAIN,

Assistant Examiners. 

8. A RELAY COMPRISING AN E-SHAPED CORE HAVING THREE PARALLEL LEGS, THE ENDS OF LEGS OF SAID CORE FUNCTIONING AS POLES, AN ELECTROMAGNETIC WINDING ABOUT THE CENTER LEG OF SAID CORE FOR ENERGIZING SAID CORE, A BRIDGE STRUCTURE OF MAGNETIZABLE MATERIAL MOUNTED UPON THE OUTER LEGS OF SAID CORE, AN ARMATURE FLAPPINGLY ENGAGED WITH SAID BRIDGE STRUCTURE AND ADAPTED TO MOVEMENT IN THE VICINITY OF THE POLES OF SAID CORE SO AS TO SWING TOWARD SAID POLES IN ACCORDANCE WITH THE ENERGIZATION OF SAID WINDING, A STATIONARY ELECTRICAL CONTACT MEMBER RELATIVELY FIXED WITH RESPECT TO SAID CORE, AND A MOVABLE ELECTRICAL CONTACT MEMBER RESPONSIVE TO MOVEMENT OF SAID ARMATURE FOR CONTACT WITH SAID STATIONARY MEMBER. 